Patent GB-419736-A (GB)
Title: Manufacture of azo dyestuffs
IPC: C09B31/08
Filed: 1933-05-17
Abstract: A diazotized amine of the benzene series not containing a nitro group is coupled with an amine of the benzene series having a free p-position to the amino group and not containing a hydroxy, alkoxy or carboxylic group in o-position to the amino group; one of the components must contain a sulphonic or carboxylic group. The resulting aminoazo compound is diazotized and coupled with a 2-benzoylaminobenzoylamino - 5 - naphthol - 7 - sulphonic acid in which the benzoyl radicles may contain substituents such as halogen or alkyl, alkoxy or nitro groups, but must not contain a free sulphonic, carboxylic, amino or hydroxy group.  The disazo dyes obtained give bluish-red shades on natural and regenerated vegetable fibres.  The following examples are given, 2-(p-benzoylaminobenzoyl)amino - 5 - naphthol - 7 - sulphonic acid or 2 - (m - benzoylaminobenzoyl)-amino - 5 - naphthol - 7 - sulphonic acid being used as the end component in each example:--(1) 4 - aminoazobenzene - 4<1> - sulphonic acid --> end component; (2) p-sulphanilic acid --> m-toluidine --> end component; (3) p-sulphanilic acid --> p-xylidine --> end component; (4) o-sulphanilic acid --> m-toluidine --> end component; (5) 3-toluidine-6-sulphonic acid --> m-toluidine --> end component; (6) 1 : 3 : 4 - xylidine - 5 - sulphonic acid --> p-xylidine --> end component; (7) 1 : 3 : 4 - xylidine - 5 - sulphonic acid --> m-toluidine - o  - methane-sulphonic acid (hydrolysed) --> end component; (8) p-aminobenzoic acid --> aniline-o -methanesulphonic acid (hydrolysed) --> end component. Other specified first components are metanilic acid, toluidinesulphonic acids in general, anisidinesulphonic acids, and m-aminobenzoic acid; when the second component contains a sulphonic or carboxylic group, aniline, toluidines, xylidines, anisidines and cresidines may be used as first components.  Other specified second components are o-toluidine and m-anisidine; m-aminobenzoic acid (as methane-o -sulphonic acid) and aniline-o- or m-sulphonic acid may also be used, if the first component does not contain a sulphonic or carboxylic group. p Specification 4768/09, [Class 2 (iii)], is referred to.  2 - (p - Benzoylaminobenzoyl)amino - 5 - naphthol-7-sulphonic acid is prepared from benzoyl chloride and 2-(p-aminobenzoyl)amino-5-naphthol-7-sulphonic acid in the presence of sodium carbonate.  2 - (m - Benzoylaminobenzoyl)amino - 5 - naphthol - 7 - sulphonic acid is prepared in corresponding manner. The Specification as open to inspection under Sect. 91 is not restricted to the use of first components not containing a nitro group, or to the use of second components not containing a hydroxy, alkoxy or carboxylic group in o-position to the amino group.  It specifies o-anisidine as a suitable second component, and includes the following example:--p-sulphanilic acid --> cresidine --> end component.  It states also that the product of example 1 is obtainable by benzoylating the dye 4-aminoazobenzene - 4<1> - sulphonic acid --> 2-(p-aminobenzoyl)amino - 5 - naphthol - 7 - sulphonic acid.  This subject-matter does not appear in the Specification as accepted.